Hand Coil Wave-Winder

[Yorkie]

Nice piece of mech engineering David, beyond my crude workshop. My coil winder is so basic but its surprising what you can do even with that. Yeah! heard about the calculator trick, not tried it. My counters binary but I can read that OK.

I take it the bobbin of new wire goes on the lower shaft and gets packed out to fit? Where did the cones come from that hold the coil former?

thanks Gary

Thanks for your kind comments guys.

To explain a bit further, the feed bobbin of wire goes on the rear shaft, the coil former goes between the cones on the centre shaft, and the front shaft carries the wire guide (presently non-existent on my winder as yet). The wire is fed beneath the guide and goes around it and out over the top of the guide which is fixed in the centre of the front shaft. The front shaft going back and forth to the extent of the 'throw' of the cam adjacent to the turning handle (as I said earlier, the cam being just a 1.5" diam washer with a brass collar soldered to it in an off centre position). As you turn the handle, the bevel gear rotates the coil former shaft, while at the same time, with each rotation, the cam moves the spring-loaded shaft with the wire guide on it. The guide moves the wire back and forth the width of the coil as it feed the wire to the coil former, so that as the coil former rotates, you achieve the wave-wound effect.

I've posted the youtube video before but no harm in doing so again. About two minutes into the video the camera pans back and you can see the whole machine in action.

As to your query about the cones Gary, I turned them, and the 'O' ring friction pulley on the lathe from black Polypenco rod. (On my woodturning lathe actually - not ideal for such a task, but at that time, I didn't have a metalworking lathe). I did actually make a wire guide, but it didn't pass the 'quality controller's' inspection - a little voice in my head that tells me 'good enough is not good enough', so I must get on with that and make a better one.

I've wound coils and transformers in the past, and at one time had a simple set-up using and electric screwdriver fixed on a board, for doing things like rewinding coils for HR headphones when they'd suffered green spot corrosion. Just wound on a full coil of 48SWG enam, and checked the resistance, then removed turns till the coil was the correct resistance then soldered the end.

At one time, Maplin sold transformer kits which were excellent - the primary was ready wound - you wound the secondary to suit your own requirements from the info supplied. I guess some law or another put the mockers on that, or maybe the just didn't sell in sufficient numbers. I've sometimes stripped the secondary off a transformer and wound my own primary.

Anyone who has wound coils by whatever means will know that the feed bobbin must rotate smoothly - not clonk about on its shaft, as any jerky movements in the wire feed is destined to break the wire, so I'll be giving that some thought.

As to Litz wire, ironically, it is in abundance quite cheaply on LW ferrite rod coils, so any coil of that inductance or less could be wound from a sacrificial LW coil, but they're only about 350uH. Rather a shame that small quantities of fine Litz are seemingly not available. Cotton or silk covered is probably just as good, but enamelled wire won't produce wave-wound coils as the turns slip off each other.

Yes Colin, I'll bring the winder to Rufforth on Saturday.

Here’s the video of the winder in action for anyone who may not have seen it before. Neat eh?:

http://www.youtube.com/watch?v=FIOocMoRsYQ